Medical expert of the article
New publications
Miliary tuberculosis
Last reviewed: 07.06.2024
All iLive content is medically reviewed or fact checked to ensure as much factual accuracy as possible.
We have strict sourcing guidelines and only link to reputable media sites, academic research institutions and, whenever possible, medically peer reviewed studies. Note that the numbers in parentheses ([1], [2], etc.) are clickable links to these studies.
If you feel that any of our content is inaccurate, out-of-date, or otherwise questionable, please select it and press Ctrl + Enter.
When the diffuse spread of tuberculosis bacteria in the body is accompanied by the appearance of many very small foci in the form of tubercula - tubercles or granulomas - nodules the size of a grain of millet (in Latin - milium), is diagnosed miliary tuberculosis).
Such tuberculous foci in this type of disease can be not only in the lungs, but also in other organs. [1]
Epidemiology
According to WHO data for 2018, TB was diagnosed in almost 10 million people, and about 1.6 million patients died from it. At the same time, experts say that globally, approximately one third of the population (especially in developing countries) may have latent infection. [2]
Miliary pulmonary tuberculosis accounts for 1-2% of all cases of tuberculosis of this localization. Its extrapulmonary forms account for at least 20% of the total TB statistics. [3]
Causes of the miliary tuberculosis
It is known that tuberculosis is caused by infection with Mycobacterium tuberculosis bacteria. The same pathogenic microorganism of the actinomycete genus, which enters the body by airborne droplets, causes multiple small focal or disseminated miliary tuberculosis.
This progressive disease can occur during primary hematogenous or lymphogenous dissemination (spread) of mycobacteria throughout the body or by affecting other organs if existing TB is untreated.
See also - Disseminated pulmonary tuberculosis.
Is miliary tuberculosis contagious or not? The contagiousness of this type of infection with tuberculosis bacilli is believed to be lower because it is spread by blood (or lymph).
Tuberculosis bacteria are transferred from sick people, and tuberculosis is contagious when there are clinical symptoms indicating that the pathogen is active. But if the mycobacterium does not lead to the development of the disease, i.e. The infection is latent (asymptomatic), the person cannot infect others.
Clinical experience shows that the result of tuberculin skin test - Mantoux test - is often false negative, and in ten cases out of a hundred the latent form eventually turns into an active (infectious) one. It is impossible to predict when this will happen. [4]
Risk factors
Undisputed risk factors for the development of miliary tuberculosis are contact with patients and conditions leading to immunosuppression - weakening of the body's immune defense.
And your immune system is compromised:
- In HIV and AIDS, miliary tuberculosis occurs in 10% of AIDS patients (see -Tuberculosis in HIV infection);
- with poor diet and chronic alcoholism;
- in cancer patients, including after chemotherapy;
- in chronic renal failure and continuous dialysis;
- due to antibody deficiency syndrome (hypogammaglobulinemia);
- in cases of long-term use of immune-suppressing drugs and corticosteroids.
Also, the risk of latent infection progressing to active TB is increased in diabetes.
Pathogenesis
Tuberculosis is an insidious and complex disease, and despite the fact that the pathogenesis of M. Tuberculosis is well known to phthisiatrists, the exact mechanism of damage in its miliary forms is not fully elucidated.
In persons infected initially with mycobacteria, the upper or posterior segments of the lung lobes are usually affected, and activation of alveolar macrophages leads to phagocytosis of the bacilli. That is, immunity limits their further multiplication, and usually in such an infection there are no clinical manifestations.
But even in the latent form, Gon foci (primary tuberculosis complexes with encapsulated inactive bacteria) may contain viable bacilli that remain dormant. And if immunity weakens, endogenous reactivation of M. Tuberculosis occurs: they begin to multiply in macrophages, spreading to nearby cells and other organs by hematogenous route.
Foci in miliary tuberculosis look like homogeneous micro-nodules (1-3 mm in diameter) of dense consistency diffusely scattered throughout the lungs. [5]
At the same time destructive changes in the lungs in miliary tuberculosis are manifested in the form of tissue infiltration by these nodules, which can unite, forming larger foci of alteration and causing fibrosis of lung tissues.
Symptoms of the miliary tuberculosis
The first signs of miliary tuberculosis are manifested by deterioration of the general condition and weakness.
The combination of symptoms, as well as signs of extrapulmonary localization of foci of lesions depend on the form of the disease.
The clinical forms of miliary tuberculosis include primarily miliary pulmonary tuberculosis, which is found in 1-7% of patients with all forms of tuberculosis. It has other typical symptoms of tuberculosis, including nocturnal hyperhidrosis (increased sweating); decreased appetite and weight loss; cough (dry or with mucousy sputum) and progressive dyspnea.
Most often the manifestations of the disease are subacute or chronic; acute miliary tuberculosis occurs less frequently.
In the acute course of generalized tuberculosis, there are chills and high hectic fever (with temperature spikes); palpitations; difficulty breathing; lividity of the skin; nausea and vomiting (indicating intoxication); and impaired consciousness. This condition - because of some similarity to typhoid fever - may be defined as typhoid or typhoid miliary tuberculosis, which most often develops in primary infection.
In the extrapulmonary form of the disease, the infection can affect several organs at once. In this case, patients are diagnosed with multiple localization miliary tuberculosis, which manifests itself with a variety of often nonspecific symptoms and leads to dysfunction of the affected organ or a certain organ system.
Thus, miliary tuberculosis of the liver may be asymptomatic, or may be accompanied by fever and hyperhidrosis and lead to hypertrophy of the organ - hepatomegaly.
Also read:
- Intestinal tuberculosis
- Pancreatic tuberculosis
- Renal tuberculosis
- Tuberculosis of the cerebral membranes (tuberculous meningitis)
One of the rarely diagnosed forms of tuberculosis of extrapulmonary localization is miliary tuberculosis of the skin, which in adults is considered a secondary form of the disease (the result of hematogenous spread of infection from the primary focus), and in children and adolescents - the primary form, with infection of the skin by contact. The most common areas affected are the face, neck, extensor surfaces of the extremities and trunk. Against the background of constitutional symptoms of tuberculosis, many small red nodules appear on the skin, which do not cause itching or pain, but very quickly turn into ulcers, so the diagnosis can be defined as miliary-ulcerative tuberculosis of the skin and subcutaneous tissues. [6]
Complications and consequences
Oxygen deficiency (respiratory distress syndrome) associated with pathologic changes in alveolar walls and impaired diffusion of oxygen into the blood; pleural empyema with fibrothorax; bronchopleural fistula formation - complications of miliary pulmonary tuberculosis.
Liver miliary tuberculosis may be complicated by increased blood bilirubin levels and jaundice, as well as fatty hepatosis and amyloid dystrophy. Intestinal obstruction is the most common complication of miliary intestinal tuberculosis.
Meningeal miliary tuberculosis (the risk of which is increased in children) can lead to increased intracranial pressure, hydrocephalus and paralysis of cranial nerves. And the consequence of the generalized form of the disease is multi-organ failure. [7]
Diagnostics of the miliary tuberculosis
Effective treatment of miliary tuberculosis and reduction of further transmission is facilitated by early diagnosis, but experts who conduct examinations of tuberculosis patients, recognize that there are certain difficulties due to the many varieties of the disease and nonspecificity of clinical manifestations of many forms.
Standard tests are required: isolation of M tuberculosis from sputum and bronchial lavage, DNA testing of tuberculosis bacillus by PCR, analysis of adenosine deaminase level in blood, COE. Histology of tissue biopsy samples is also performed. [8]
Read more:
- Laboratory diagnosis of tuberculosis
- Tuberculosis: detection of Mycobacterium tuberculosis
- Methods for detecting tuberculosis
How instrumental diagnostics is performed, the main method of which remains radiography, and ultrasound, high-resolution CT and MRI can be used to clarify the diagnosis, in detail in the publication - Instrumental diagnostics of tuberculosis.
Miliary tuberculosis is visualized on chest X-ray by small focal dissemination of both lungs, a cluster of multiple, well-defined, diffuse, scattered fibronodular blackouts. Some patients may present with unilateral pleural effusion with thickening of the visceral and parietal pleura.
Differential diagnosis
Differential diagnosis is important: miliary pulmonary tuberculosis should be distinguished from cryptococcosis and pulmonary sarcoidosis, from malignant pleural mesothelioma; miliary tuberculosis of the brain - from meningococcal or staphylococcal meningitis; cutaneous miliary tuberculosis requires particularly careful differentiation with dermatologic diseases, with rashes in syphilis (tuberculous syphilides), etc.
More information in the materials:
Who to contact?
Treatment of the miliary tuberculosis
The main treatment of tuberculosis of any form is etiotropic, lasting 6-12 months; the main drugs are anti-tuberculosis antibacterial drugs: Isoniazid, Rifampicin, Macrozid 500 (Pyrazinamide, Pyrazidine), Sodium para-aminosalicylate and others.
Read more about their side effects, contraindications, methods of use and dosage in the publication - Tuberculosis Pills.
In abscessed foci of lesions and tissue necrosis, surgical treatment is performed.
Prevention
The main preventive measure is BCG vaccination or tuberculosis vaccination.
Also read:
In cases of detected latent infection, preventive preventive treatment of tuberculosis is possible.